My 59' has shims from the factory, not sure what degree they are. I don't believe the axle it's self has any added caster. I haven't found anything in the assembly manual that states having caster made into the axle.

~ Craig
1958 Viking 4400
"The Book of Thor"
Read the story in the DITY
1960 Chevrolet C10
"A Family Heirloom"
Follow the story in the DITY Gallery
'59 Apache 31, 327 V8 (0.030 over), Muncie M20 4 Speed, GM 10 Bolt Rear... long term project (30 years and counting)

If you don't like driving yourTruck, you won't drive yourTruck..| Living life in the SLOW lane